Base Layer and Thermals

Is There a Difference Between a Base Layer and Thermal Underwear?

What is the difference between a base layer and thermal underwear? The two types of clothing are similar in that they both consist of fabrics worn beneath other clothes to keep you warm. However, both base layers and thermals help regulate your body temperature by absorbing sweat and keeping it close to the skin. Thermal underwear and a base layer insulate against cold temperatures by trapping air. Both are the same thing but are known by different names. There is no difference between the two.

Moisture-Wicking

Moisture-wicking is a term that is often heard in the sports world. Moisture-wicking fabrics are designed to move sweat away from the skin, keep the body dry and comfortable, and allow sweat to evaporate as quickly as possible. Some moisture-wicking fabrics include wool, polyester fleece, and synthetic materials. This helps keep you dry and comfortable.

Breathable Fabric

Breathable fabric facilitates the passage of water vapor from the inside to the outside of a garment. There are two types of temperature-regulating materials: base layers and thermals. Base layer and thermals are worn next to the skin and thus provide insulation, warmth, and wicking.

Stretchable Fabric

Stretchable fabric, also commonly referred to as spandex or elastane, is an amazingly versatile material. It can be found in hundreds of different products, all of which utilize the elasticity and stretch of the fabric for various purposes. Base layers are usually made up of stretchable material, so they cling tightly to your skin. This provides warmth by trapping your body heat next to your skin and helps prevent chafing from tight clothing against sensitive areas.

Odor-resistant

Many winter activities like hiking, snowshoeing, and skiing can make you perspire profusely. This is an unpleasant experience. Luckily, with advances in technology, some fabrics maintain their insulation ability even when wet. This is the first line of defense against the cold is a base layer. Base layers are usually made of wool or synthetic materials like polyester. These garments trap air next to the skin to keep the body warm and dry. Some brands treat their fabric with odor-resistance chemicals to prevent any unwanted smells.

Heat Retention

Heat retention is typically measured by the ability to insulate, dry, and the care required. A base layer retains heat because it is generally made of a material that can wick moisture away from your skin. A thermal has many layers that trap warm air in between them. If you wear more layers, the warmer you will be.

A base layer needs to be close fitting and loose enough for mobility. They also need to be lightweight and not too tight. A base layer dries quickly because it is made of a material that wicks moisture away from your skin. Both thermals and base layers will do this as they are the same product.